TM1638 is a LED display driver device from Titan Micro. It is an 8-bit parallel and serial data input device that includes a display RAM, a key scan interface, LED control registers, and a common data bus. The device features 28 pins in a SOIC-300mil package that is RoHS (Restriction of Hazardous Substances) compliant. It has multiple 8-bit parallel drive ports for up to 56 LEDs. Its serial data input mode allows for easy connection of microcontroller ports. The device also offers a 4-bit key scan interface and up to 128 addressable memory locations that contain the data used to drive the LEDs. It has built-in oscillator and refresh functions for fast LED blinking and display time scale control. The device delivers 5V/3.3V Low-Voltage Level and CMOS compatible serial data input. It supports multiple LED drive operations (static, continuous, and multiple patterns) and is suited for applications such as digital clock displays, audio frequency indicators, temperature readout displays, and process indicators.